Rhythmic patterns:
Look for repeated patterns of erosional areas adjacent (in a longshore
direction) to accretional areas. These are likely due to the presence of
giant cusps in one of the surveys and either a) giant cusps in the other survey
were not present or b) were shifted alongshore. During storms, wave runup
in low embayments between adjacent cusps may attack dunes, causing net
erosion, whereas landward of prominent cusps the dunes may be protected by
the wide beach.